In an engine, an automatic transmission or the like of an automobile, for example, a control valve for controlling the pressure of fluid such as fuel or oil or for changing the passage of fuel or oil has been used in many cases. If foreign matter contained in fluid has intruded into such control valve, its normal operation might be inhibited. Thus, a filter is attached to such control valve for catching foreign matter contained in fluid.
JP-2002-285966-A discloses a filter in which a frame body (53, the number in the brackets corresponds to the reference numeral in JP-2002-285966-A) is dividable at its ends. At the ends of the frame body (53), an engagement portion (55) for engaging the both ends and a retaining portion (56) for retaining the engaged state are provided.
The frame body (53) includes a pair of parallel ring frames (53a) and plural ribs (53b) connecting the ring frames (53a). Window parts (53c) defined by the ring frames (53a) and the ribs (53b) are provided with a mesh member (54). As the engagement portion (55), a hook part (55a) is provided at one end of the frame body (53), and the rod (55b) to be engaged therewith is provided at the other end of the frame body (53). And, as the retaining portion (56), a claw part (56) is provided at the other end in the vicinity of the rod (55b). A width of the hook part (55a) corresponds to a distance between the pair of ring frames (53a). After the hook part (55a) at the one end is hooked on the rod (55b) at the other end, the resulting engaged state is retained by the claw part (56), thereby attaching the filter to a control valve without disconnection.
In JP-2002-285966-A, when the hook part (55a) is engaged with the rod (55b), the tip of the hook part (55a) overlaps with the window part (53c) of the frame body (53), and the window part (53c) is narrowed. Therefore, an effective area of the mesh member (54) provided in the window parts (53c) is reduced. Further, since the hook part (55a) has a large width corresponding to the distance between the ring frames (53a), the window part (53c) is further narrowed when the hook part (55a) is engaged with the rod (55b).